Bioassay of insulin MCQs With Answer

Bioassay of insulin MCQs With Answer

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Bioassay of insulin MCQs With Answer is a focused study tool for B. Pharm students to master insulin pharmacology, potency estimation, and analytical bioassay methods. This guide covers in vivo hypoglycaemic assays, receptor binding and in vitro cell-based potency tests, immunoassays versus biological assays, reference standards (IU), dose–response curves, ED50/EC50 determination, parallel line analysis, validation parameters, and regulatory aspects. Practical considerations include animal models, fasting protocols, glucose measurement techniques, sample preparation, and stability issues. Emphasis on interpretation of potency results, assay sensitivity, accuracy and precision equips students to design and evaluate insulin bioassays confidently. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which parameter specifically measures the biological potency of an insulin preparation?

  • Concentration in mg/mL
  • International Units (IU)
  • pH of solution
  • Osmolality

Correct Answer: International Units (IU)

Q2. The standard in vivo bioassay for insulin potency most commonly measures which physiological effect?

  • Increase in heart rate
  • Decrease in blood glucose (hypoglycaemic response)
  • Increase in body temperature
  • Change in urine output

Correct Answer: Decrease in blood glucose (hypoglycaemic response)

Q3. Which animal is most commonly used for classical hypoglycaemic bioassays of insulin?

  • Guinea pig
  • Rabbit
  • Mouse
  • Dog

Correct Answer: Mouse

Q4. ED50 in an insulin bioassay refers to:

  • The dose causing 50% mortality
  • The dose producing 50% of maximal glucose-lowering effect
  • The dose required to reach 50 IU
  • The time to reach 50% of peak effect

Correct Answer: The dose producing 50% of maximal glucose-lowering effect

Q5. Which analytical method measures insulin concentration but not necessarily biological potency?

  • In vivo hypoglycaemic assay
  • Cell-based glucose uptake assay
  • ELISA (immunoassay)
  • Receptor activation bioassay

Correct Answer: ELISA (immunoassay)

Q6. Parallel line assay is used in bioassay data analysis to:

  • Compare slopes of degradation profiles
  • Determine parallelism between test and reference dose–response curves
  • Measure glucose concentrations enzymatically
  • Estimate immunogenicity of insulin

Correct Answer: Determine parallelism between test and reference dose–response curves

Q7. A key advantage of an in vitro receptor binding assay for insulin is:

  • It directly measures hypoglycaemia in animals
  • It assesses receptor affinity without animal use
  • It determines sterilization efficiency
  • It quantifies endotoxin content

Correct Answer: It assesses receptor affinity without animal use

Q8. When validating an insulin bioassay, which parameter assesses the closeness of measured values to the true value?

  • Precision
  • Specificity
  • Accuracy
  • Robustness

Correct Answer: Accuracy

Q9. In glucose measurement for insulin bioassays, which enzymatic method is widely used?

  • Biuret method
  • Glucose oxidase–peroxidase (GOD-POD) method
  • Bradford assay
  • Lowry method

Correct Answer: Glucose oxidase–peroxidase (GOD-POD) method

Q10. The term “bioactivity” of insulin primarily refers to:

  • The molecular weight of insulin
  • The ability to lower blood glucose via receptor activation
  • The batch-to-batch visual clarity
  • The solubility in water

Correct Answer: The ability to lower blood glucose via receptor activation

Q11. Which statistical test is often applied to compare multiple dose groups in a bioassay?

  • Student’s t-test for two independent samples only
  • ANOVA (analysis of variance)
  • Chi-square goodness-of-fit
  • Pearson correlation

Correct Answer: ANOVA (analysis of variance)

Q12. Parallelism in bioassay results indicates:

  • The test sample is identical chemically to the reference
  • The dose–response slopes of test and reference are statistically parallel
  • The assay has zero variability
  • The reference standard is expired

Correct Answer: The dose–response slopes of test and reference are statistically parallel

Q13. Which factor can falsely lower apparent potency in an insulin bioassay?

  • Presence of active reference standard
  • Degradation of insulin to inactive forms
  • Use of fasting animals
  • Properly calibrated glucose meter

Correct Answer: Degradation of insulin to inactive forms

Q14. In expressing insulin potency, the unit IU is defined relative to:

  • A fixed mass in mg
  • An international reference preparation
  • The molar concentration in moles/L
  • The pH of the formulation

Correct Answer: An international reference preparation

Q15. During animal hypoglycaemic assays, why are animals typically fasted before dosing?

  • To increase variability in glucose measurements
  • To standardize baseline glucose and enhance assay sensitivity
  • To prevent insulin absorption
  • To induce stress-related hyperglycaemia

Correct Answer: To standardize baseline glucose and enhance assay sensitivity

Q16. Which of the following is a limitation of immunoassays (ELISA/RIA) for insulin potency?

  • They directly measure glucose lowering in vivo
  • They cannot distinguish active from inactive degraded insulin forms reliably
  • They are always less sensitive than biological assays
  • They require sacrificing large numbers of animals

Correct Answer: They cannot distinguish active from inactive degraded insulin forms reliably

Q17. What does EC50 represent in a cell-based insulin potency assay?

  • The concentration that produces 50% of maximal cellular response
  • The effective count of 50 cells
  • The exposure concentration for 50 minutes
  • The enzyme concentration at 50°C

Correct Answer: The concentration that produces 50% of maximal cellular response

Q18. Which assay design element reduces bias and increases reliability of bioassay results?

  • Using a single animal per dose
  • Blinding the operator to sample identity
  • Not randomizing dose order
  • Measuring glucose only once per animal

Correct Answer: Blinding the operator to sample identity

Q19. In bioassay validation, the term “sensitivity” refers to:

  • The smallest change in potency that can be detected
  • The assay’s resistance to temperature changes
  • The maximum dose tested
  • The number of animals used

Correct Answer: The smallest change in potency that can be detected

Q20. Which regulatory or pharmacopeial element often provides reference methods for insulin bioassays?

  • USP (United States Pharmacopeia)
  • ISO color chart
  • EPA pesticide guidelines
  • ICH stability storage chart

Correct Answer: USP (United States Pharmacopeia)

Q21. Matrix effects in bioassay samples can lead to:

  • Improved assay reproducibility always
  • Interference causing under- or over-estimation of potency
  • Automatic standardization of reference
  • Sterilization of the sample

Correct Answer: Interference causing under- or over-estimation of potency

Q22. A potency estimate expressed as IU/mg indicates:

  • The immunogenic potential per mg
  • The biological units of activity per milligram of material
  • The mass loss after storage
  • The number of insulin molecules per mg

Correct Answer: The biological units of activity per milligram of material

Q23. Which sample handling practice helps preserve insulin bioactivity before assay?

  • Repeated freeze–thaw cycles
  • Exposure to light and room temperature
  • Storage at recommended cold temperatures and minimal handling
  • Acidifying the sample to pH 2

Correct Answer: Storage at recommended cold temperatures and minimal handling

Q24. Which outcome suggests non-parallelism between test and reference curves?

  • Equal slopes with different intercepts
  • Different slopes that are statistically significant
  • Identical dose–response across all doses
  • Minimal variability in replicates

Correct Answer: Different slopes that are statistically significant

Q25. The main ethical consideration in animal bioassays that B. Pharm students must observe is:

  • Maximizing animal numbers to increase data
  • Using humane endpoints and following the 3Rs (Replacement, Reduction, Refinement)
  • Avoiding any documentation of welfare
  • Depriving animals of water permanently

Correct Answer: Using humane endpoints and following the 3Rs (Replacement, Reduction, Refinement)

Q26. Which degradation product of insulin is most likely to reduce biological potency?

  • Intact native insulin dimer
  • Oxidized methionine residues or deamidated forms
  • Properly folded monomeric insulin
  • Purified reference standard

Correct Answer: Oxidized methionine residues or deamidated forms

Q27. In designing a dose–response series for an insulin bioassay, the dose range should:

  • Be narrow and around a single dose only
  • Span doses that cover from no effect to near-maximal effect
  • Always use only the highest dose
  • Exclude the reference standard

Correct Answer: Span doses that cover from no effect to near-maximal effect

Q28. Which is a reason to prefer cell-based potency assays over immunoassays?

  • Cell-based assays measure biologically relevant receptor-mediated responses
  • They are cheaper than buffer blanks
  • They never require validation
  • They provide direct chemical structure information

Correct Answer: Cell-based assays measure biologically relevant receptor-mediated responses

Q29. If an assay shows high intra-assay variability, this indicates problems with:

  • Between-day reproducibility only
  • Precision within the same run
  • Global regulatory compliance
  • Reference standard potency only

Correct Answer: Precision within the same run

Q30. Which practice improves reliability when comparing a test insulin to a reference standard?

  • Using different assay conditions for test and reference
  • Running test and reference samples in the same assay under identical conditions
  • Not including replicates
  • Altering the pH only for the test sample

Correct Answer: Running test and reference samples in the same assay under identical conditions

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